This invention relates to tuyeres for metallurgical vessels.
In metallurgical vessels such as basic oxygen furnaces, oxygen is injected into a molten metal bath, such as pig iron, through a top lance for the purpose of oxidizing carbon, silicon, and other impurities. In order to promote homogeneity of the molten metal bath, inert gases such as argon, nitrogen, or carbon dioxide are injected through bottom tuyeres so as to promote mixing.
Such prior art bottom tuyeres have generally comprised a pipe opening into the lower end of the vessel. Inert gas was then discharged through the pipe into the molten metal bath thereby inducing motion in the bath which resulted in mixing. It has been found that when a single tuyere pipe is employed, gas flow at the center of the pipe tends to be greater than along its inner surface whereby the cooling effect of the gases with respect to the tuyere pipe is diminished. As a result, the tuyere pipes tend to become relatively hot resulting in rapid tuyere and refractory wear.